The invention relates to a device which prevents an automobile engine starter from engaging once an engine is running by using the running engine vacuum to cause the starter circuit to open. This prevents damage to the gears of a starter, which can be stripped if starting is attempted when the engine is running. The invention is particularly beneficial to the hearing impaired, whom due to their difficulty in hearing may not be aware that an automobile engine is running and may try to restart the engine. This could cause damage and endanger the automobile occupants.